Configuration item

Create a ConfigMap

This section describes how to create a ConfigMap in the Container Application Service console.

Procedure

1. Log on to the Container Application Service console. In the navigation pane on the left, click Configuration > ConfigMaps.

2. Click Create. On the Create ConfigMap page, set the following parameters:

   • Namespace: Select a namespace. If you do not select a namespace, the system uses default.

   • Name: Enter a name for the ConfigMap. The name must be unique within the namespace and can be up to 32 characters long.

   • Configuration Source:

     • Key-value pair: The key represents the file name, and the value represents the file content.

     • File: Upload a file to create the ConfigMap.

3. After you complete the configuration, click Create.

Use a ConfigMap

You can use a ConfigMap in a pod. The main scenarios are as follows:

• Define pod environment variables with a ConfigMap

• Set command-line arguments with a ConfigMap

• Use a ConfigMap in a volume

  Important

  When you use a ConfigMap in a pod, both must be in the same namespace.

For more information about ConfigMaps, see Configure a Pod to Use a ConfigMap.

Define pod environment variables with a ConfigMap

You can use a ConfigMap to define environment variables in a pod using valueFrom to reference the ConfigMap data.

1. Log on to the Container Application Service console. In the navigation pane on the left, click Workloads > Pods.

2. Click Create from YAML. Enter the following content in the editor and click Create.

   The following is an example of orchestration.

   apiVersion: v1
   kind: Pod
   metadata:
      name: config-pod-1
      namespace: yournamespace  # Replace with your namespace name
   spec:
      containers:
      - name: test-container
        image: busybox
        command: [ "/bin/sh", "-c", "env" ]
        env:
        - name: SPECIAL_LEVEL_KEY
          valueFrom:                             # Use valueFrom to specify that the env references the value of the ConfigMap
          configMapKeyRef:
            name: special-config               # The name of the referenced ConfigMap
            key: SPECIAL_LEVEL                 # The key of the referenced configuration item
      restartPolicy: Never

Set command-line arguments with a ConfigMap

You can use a ConfigMap to set command or argument values in a container. To do this, use the environment variable substitution syntax $(VAR_NAME).

1. Log on to the Container Application Service console. In the navigation pane on the left, click Workloads > Pods.

2. Click Create from YAML. Enter the following content in the editor and click Create.

   The following is an orchestration example.

   apiVersion: v1
   kind: Pod
   metadata:
      name: config-pod-3
      namespace: yournamespace  # Replace with your namespace name
   spec:
      containers:
      - name: test-container
        image: busybox
        command: [ "/bin/sh", "-c", "echo $(SPECIAL_LEVEL_KEY) $(SPECIAL_TYPE_KEY)" ]
        env:
        - name: SPECIAL_LEVEL_KEY
          valueFrom:
          configMapKeyRef:
   	 name: special-config
   	 key: SPECIAL_LEVEL
        - name: SPECIAL_TYPE_KEY
          valueFrom:
          configMapKeyRef:
   	 name: special-config
   	 key: SPECIAL_TYPE
      restartPolicy: Never

   After the pod runs, the following output is returned.

   very charm

Use a ConfigMap in a volume

You can also use a ConfigMap in a volume. To do this, specify the ConfigMap name in the `volumes` section. Each key-value pair in the ConfigMap data becomes a file in the directory specified by `mountPath`. The key becomes the file name and the value becomes the file content. In this example, the path is /etc/config.

1. Log on to the Container Application Service console. In the navigation pane on the left, click Workloads > Pods.

2. Click Create from YAML. Enter the following content in the editor and click Create.

   The following is an example of an orchestration.

   apiVersion: v1  
   kind: Pod  
   metadata:  
      name: config-pod-4  
      namespace: yournamespace  # Replace with your namespace name  
   spec:  
      containers:  
      - name: test-container  
        image: busybox  
        command: [ "/bin/sh", "-c", "ls /etc/config/" ]   # List the file names in this directory  
        volumeMounts:  
        - name: config-volume  
        mountPath: /etc/config  
      volumes:  
      - name: config-volume  
        configMap:  
        name: special-config  
      restartPolicy: Never  

   After the pod runs, the output lists the keys from the ConfigMap.

   SPECIAL_TYPE SPECIAL_LEVEL

Modify a ConfigMap

Changes to a ConfigMap can affect the applications that use it.

Procedure

1. Log on to the Container Application Service console. In the navigation pane on the left, click Configuration > ConfigMaps.

2. On the configuration item list page, click an item's Name to open its details page.

3. You can make the following changes:

   • Click Edit, modify the existing ConfigMap data, and click Submit.

   • Click Add Configuration Item Data, enter a new variable name and value, and click Submit.

View configuration items

Prerequisites

A ConfigMap has been created.

Procedure

1. Log on to the Container Application Service console. In the navigation pane on the left, click Configuration > ConfigMaps.

2. On the configuration item list page, click the Name of a configuration item to view its details.